Regional cerebral blood flow with manual internal cardiac massage versus direct mechanical ventricular assistance.

Study Hypothesis: Previous studies have not discerned the best method for generating regional cerebral blood flow during internal cardiac massage. We hypothesized that regional cerebral blood flow generated by a mechanical method--direct mechanical ventricular assistance (DMVA)--would be superior to manual internal cardiac massage (MAN).

Study Population: Twelve adult Yucatan minipigs weighing more than 44 kg each were studied.

Median frequency--a new parameter for predicting defibrillation success rate.

Study Hypothesis: Current American Heart Association guidelines recommend immediate defibrillation of ventricular fibrillation. When this is unsuccessful, there are no guidelines to help determine the optimum time at which to defibrillate after the administration of an alpha-adrenergic agonist. Previous studies have shown that the median frequency of the ventricular fibrillation ECG signal correlates with myocardial perfusion during CPR.

Estimation of myocardial ischemic injury during ventricular fibrillation with total circulatory arrest using high-energy phosphates and lactate as metabolic markers.

Study Objective: To define the time course of myocardial ischemic injury using high-energy phosphate (HEP) depletion and the cessation of lactate production as metabolic markers.

Setting: Data were collected in a laboratory animal model.

Type Of Participants: Ten immature mixed breed swine weighing 23.

Hemodynamic effects of 1-[3,4-dihydroxyphenyl]-1,2-diaminoethane versus norepinephrine during ventricular fibrillation and cardiopulmonary resuscitation.

We hypothesized that substitution of the hydroxyl group (OH) on the beta carbon of norepinephrine (NE) with an amino group would yield a compound, 1-(3,4-dihydroxyphenyl)-1,2-diaminoethane (DHPDAE), that would maintain the hemodynamic properties of NE during CPR, but would decrease the rate of post-defibrillation dysrhythmias. Six mixed breed swine weighing greater than 28 kg were studied. The animals were instrumented for cerebral (CBF) and myocardial blood flow (MBF) measurements.